Battery charger



FIG. 1 is a front, right side and top perspective view of a battery charger showing my new design;

FIG. 2 is a rear, right side and top perspective view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a front side elevational view thereof;

FIG. 5 is a rear side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for a battery charger, as shown and described. 